1. Field of the Invention
The present invention relates to zeolite-based organochromium catalyst compositions especially suitable for the polymerization of 1-olefins such as ethylene.
2. Description of the Prior Art
Organochromium materials such as pi-bonded organochromium [II] compounds are known to be especially effective catalysts for the polymerization of olefins such as ethylene. Such materials by themselves, however, are incapable of initiating the polymerization reaction, and, for this reason, such organochromium compounds are generally adsorbed or deposited on an inorganic oxide catalyst support having a high surface area. Karapinka et al; U.S. Pat. No. 3,709,853, issued Jan. 9, 1973, for example, discloses bis-(cyclopentadienyl) chromium [II] compounds supported on a variety of porous, amorphous silica materials to thereby form effective ethylene polymerization catalysts.
Notwithstanding the existence of such known polymerization catalysts comprising supported organochromium materials, there is a continuing need to identify catalysts and catalyst support materials which can be effectively employed in the commercially important field of olefin polymerization. Accordingly, it is an object of the present invention to provide novel organochromium based catalyst compositions which are especially suitable for promoting polymerization of 1-olefins such as ethylene. It is a further object of the present invention to provide an olefin polymerization process employing such novel chromium-based catalyst compositions.
These and other objectives can be realized by means of the composition and process embodiments of the invention described herein.